Transmitter



M. R. MYERS. TRANSMITTER. APPLICATION FILED 0c.22. 1919.

Patented Jan. 25,1921. 2 SHEETS-SHEET 1.

tr at u WITNESSES ATTORNEYS M. R. MYERS. TRANSMITTER.

APPLICATION men use. 22, 1919.

Patented Jan. 25, 1921.

2 SHEETS-SHEET 2.

l/I/VENTOR WITNESSES MWM 4 A NOR/VETS PATENT OFFICE.

MARSHALL RALPH MYERS, O1 AFTON, IOWA.

TRANSMITTER.

Specification of Letters Patent.

Patented Jan. 25, 1921.

' Application filed December 22, 1919. Serial No. 346,559.

' To all whom it may concern:

Be it known that I, \lARsHALL RALPH MYnns, a citizen of the United States, and a resident of Afton, in the county of Union and State of Iowa, have invented certain new and useful Improvements in Transmitters, of which the following is a specification.

M invention is an improvement in transmitters, and has for its object to provide a device of the character specified, especially adapted to withstandheavy currents of electricity such as are used in wireless telephony.

A further object is to provide a transmitter that can be used from any angle, and-for this reason, especially adapted for use with flying machines.

in the drawings:

Figure 1 is a front view with the diaphragm the transmitter casing remover,

Fig. 2 is a vertical section,

Fig. 3 is a front view with the diaphragm and the front head removed,

Fig. i is a rear view with the rear head removed,

Fig. 5 is a diagrammatic view showing the wiring of the electrodes,

F 6 is an enlarged section of one of the electrodes,

Fig. '7 is a plan view of one of the electrode supports.

In the present embodiment of the invention, the improved transmitter comprises a suitable casing in the form of a body 1 and heads 2 and 3 detachably connected with the body, the head 2 carrying at its center the mouth piece 4. The ends of the body are rabbeted as shown, the rabbets being oppositely arranged, and the heads have threaded flanges for engaging within the rabbets.

A ring 5 is threaded into the body, the body being internally threaded for this purpose, and this ring has a central opening. The central opening is closed by a disk 6, and it will be seen that the ring 5 is counterbored at the central opening at the rear face to form a rabbet for receiving the edge of the disk, and the disk is secured to the ring by,

means of screws 7.

The ring 5 has a marginal flange or rib 8 extending forwardly from the front face thereof, and the diaphragm 9 is held between the head 2 and the body, the edges of the diaphragm being grasped between the annular shoulder by rabbeting the body and the flange of the head.

The flange 8 of the ring 5 has an annular extension 10, which bears against the inner face of the diaphragm inside. the rib of the head 2, as clearly shown in Fig. 2.

An annular series of electrodes is arranged about the axis of the casing 1, between the diaphragm and the ring Each of these electrodes as shown more particularly in Fig. 6 consists of a central portion 11 and lateral portions 12, the central portion being carbon dust pressed to an oval shape, and held between the lateral sections 12 which are shaped to fit the convex faces of the central section,

and these sections are held together in any suitable or desired manner.

A substantially spoon-shaped support 13 is provided for each electrode, these supports having one end provided with an opening for engagement by a screw, to connect the said end to the ring and the bodies of the supports extend radially inward beyond the Wall of the central opening. Each support has a transverse groove as clearly shown, between that portion which engages the-electrode and that portion which is connected to the ring. Thus each electrode is arranged between a support 13 and the diaphragm, abutting the support, and being very close to the diaphragm.

A ring or annular frame 14 is secured to the forward face of the ring ust within the flange 8, and a second ring or annular frame 15 is superposed on the ring 14, and is secured thereto by means of bolts and nuts 16. The bolts are passed through the rings or frames from the front to the rear, andto the ring 5, and are engaged by the nuts on the rear face of the ring.

A wire indicated at 17 is connected with all of the electrodes, the wiring being arranged between the bolts 16 and the electrodes. The wire is passed from between the rings inwardly, about the electrode, and outwardly around the succeeding bolt, and thence inwardly to wrap about the second electrode and outward to pass about a second bolt. This arrangement is continued until all of the electrodes are connected to the frames 14.15. Thus the wires bind the electrode sections together, as well as connect them to the frames.

The ends of the wire 17 pass through insulating tubes 18 in the ring 5, to a connection with binding posts 19 on the rear face of the ring, and the wires of the transmitting cable 20 are connected with the binding posts.- An adjusting screw 21 is provided V by means of the screws for each electrode, each screw being threaded through the disk 6 into engagement with the support of the adjacent electrode, and by means of these screws, the electrodes may be adjusted toward and from the diaphragm, the resiliency of the support moving the electrodes away from the diaphragm.

Means is provided for dampening the vibration of the diaphragm. The said-means is in the form of resilient strips 22 each of which is secured to a screen 23 which is secured to the inner face of the head 2, which connect the strips 22 to the screen. These strips at the opposite ends from the screws pass through bearings 25 on the diaphragm.

In F 5 is shown diagrammatically the wiring. As shown, the lateral sections of the adjacent electrodes indicated generally at 26 are connected by cross wires 27, all of the electrodes being arranged in a circuit 28 having a source of electrical energy 29 as for instance, a battery.

That lateral section 12 adjacent to the diaphragm of each electrode is connected to that section of the succeeding electrode which is remote from the diaphragm by the cross wires 27. That is, all of the electrodes are arranged in series in the circuit 28. T his circuit is connected with the primary 30 ot a coil whose secondary 31 is interposed in the circuit 32 ofthe receiver 33.

In the improved transmitter, each elect trode consists'in efiect of two disks concaved on their adjacent 1 cos to form a cavity which is filled with a dish of carbon shaped to fit the cavity. The diaphragm is under tension and will therefore carry vibrations better and will pick up lower sounds. On the screen at the center of the mouth piece there is arranged a conical member 34, which directs the sound toward the electrodes. Each electrode can be ad justed-separately. A

The annular rib 8 of the ring?) engages the rear face of the diaphragm, and it will be evident that by turning the ring to move the rib toward or from the diaphragm, the tension of the diaphragm may be varied.

I claim 2- 1. A transmitter comprising a casing carrying a diaphragm held firmly at its e lges by the casing, a ring adjustable in the casing toward and from the diaphragm and provided with an annular rib spaced inwardly from the casing for engaging the diaphragm to tension the same, an annular series of electrodes supported in rear of the diaphragm coaxial therewith, and means for adjusting the individual electrodes toward and from the diaphragm, each of said electrodes comprising concave lateral sections, and a central section of granulated carbon held between the lateral sections and fitting the concave faces. V

2. A transmitter comprising a casing carrying a diaphragm held firmly at itsedges by the casing, a ring adjustable in the easing toward and from the diaphragm and provided with means for engaging the diaphragm to tension the same, an annular series of electrodes supported in rear of the diaphragm coaxial therewith and means for adjusting the individual electrodes toward. and from the diaphragm, each of said electrodes comprising concave lateral sections and a central section of granulated carbon fitting the concave faces.

in witness whereof I have hereunto set my hand.

MARSHALL RALPH MYERS. 

